Hand dermatitis may result from exposure to numerous environmental irritants, including soaps, detergents, chemicals, frequent hand washing, and continual or repeated glove use. Susceptible individuals are predisposed to developing dermatitis due to the sensitive nature of their skin, such as atopic eczema.
Hand dermatitis can be managed by (1) using topical steroids (e.g., hydrocortisone), (2) using protective gloves to avoid contact with irritants, (3) identifying and reducing exposure to irritants and allergens, and (4) keeping the hands consistently lubricated with emollients.
Commercial products to treat dermatitis are frequently emulsions, especially semisolid emulsions (i.e., creams). Creams are the most popular delivery system for topical drugs because of cosmetic and aesthetic properties. Emulsifiers, typically surfactants that penetrate the stratum corneum and disrupt the barrier, are required ingredients of emulsions and typically at least one and preferably two low molecular weight emulsifiers are used in commercial creams.
It has been established that the ingredients present in topical therapeutic treatments (i.e., creams, lotions, and ointments) may prevent healing or may even worsen the damaged skin of the hands. The culprit chemicals have been preservatives or excipients to which the individual had an allergic contact dermatitis. Frequent hand washings can over-dry and cause chapping of sensitive hands. In order to counteract this adverse effect of frequent exposure to soap and water, moisturizers and lubricants are commonly used.
Irritating materials such as detergents are commonly present as emulsifiers in topical creams and lotions. These materials provide an additive or synergistic effect to increase the potential for irritation of the treated skin caused by frequent skin washing or topical pharmacologic treatment of irritated or potentially irritated skin. Moreover, many therapeutic agents, such as retinoic acid, benzoyl peroxide, sunscreens, and anti-perspirants, which are incorporated into creams and lotions to treat skin disease, are themselves irritating to skin.
A significant need exists for an emulsion that can be utilized as a moisturizer, as a protectant, or as a vehicle for potentially irritating therapeutic agents that will reduce, or at least not potentiate, irritation of sensitive or diseased skin. Such an emulsion should be stable, cosmetically elegant, compatible with a wide variety of drug substances, and most importantly be non-irritating to sensitive or dermatitic skin.